package dataStructure.xmg1.a13.map;

import dataStructure.xmg1.a13.printer.BinaryTreeInfo;
import dataStructure.xmg1.a13.printer.BinaryTrees;

import java.util.LinkedList;
import java.util.Objects;
import java.util.Queue;

/**
 * @author: vince_zww
 * @date: 2021/6/16 10:11
 * @desceription:
 */
public class HashMap<K, V> implements Map<K, V> {
    private static final boolean RED = false;
    private static final boolean BLACK = true;
    private int size;
    private Node<K, V>[] table;
    private static final int DEFAULT_CAPACITY = 1 << 4;
    private static final float DEFAULT_LOAD_FACTOR = 0.75f;

    public HashMap(){
        table = new Node[DEFAULT_CAPACITY];
    }


    @Override
    public int size() {
        return size;
    }

    @Override
    public boolean isEmpty() {
        return size == 0;
    }

    @Override
    public void clear() {
        if (size==0) return;
        size = 0;
        for (int i = 0; i < table.length; i++) {
            table[i] = null;
        }
    }

    @Override
    public V put(K key, V value) {
        resize();

        int index = index(key);
        //取出index位置的红黑树根节点
        Node<K, V> root = table[index];
        if (root == null) {
            root = createNode(key, value, null);
            table[index] = root;
            size++;
            fixAfterPut(root);
            return null;
        }
        //哈希冲突，添加新的节点到红黑树上
        // 添加的不是第一个节点
        // 找到父节点
        Node<K,V> parent = null;
        Node<K,V> node = root;
        int cmp = 0;
        K k1 = key;
        int h1 = hash(k1);
        Node<K,V> result = null;
        boolean searched = false; //是否已经搜索过这个key
        do{
//            cmp = compare(key, node.key, h1, node.hash);
            parent = node;
            K k2 = node.key;
            int h2 = node.hash;
            if (h1 > h2) {
                cmp = 1;
            } else if (h1 < h2) {
                cmp = -1;
            }else if (Objects.equals(k1,k2)){// 相等
                cmp = 0;
            } else if (k1 != null && k2 != null
                    && k1 instanceof Comparable
                    && k1.getClass() == k2.getClass()
                    && (cmp = ((Comparable) k1).compareTo(k2)) != 0) {


            } else if (k1 != null && k2 != null
                    && k1.getClass() == k2.getClass()
                    && k1 instanceof Comparable
                    && (cmp = ((Comparable) key).compareTo(k2)) != 0) {
//                cmp = ((Comparable) key).compareTo(k2);
            } else if (searched) {//已经扫描了
                cmp = System.identityHashCode(k1) - System.identityHashCode(k2);
            } else { // searched==false;还没有扫描，然后再根据内存地址大小决定左右
                if (node.left != null && (result = node(node.left, k1)) != null
                        || (node.right != null && (result = node(node.right, k1)) != null)) {
                    //已经存在这个key
                    node = result;
                    cmp = 0;
                } else { // 不存在这个key
                    searched = true;
                    cmp = System.identityHashCode(k1) - System.identityHashCode(k2);
                }

            }

            if (cmp > 0) {
                node = node.right;
            } else if (cmp < 0) {
                node = node.left;
            } else {// 相等
                V oldValue = node.value;
                node.key = key;
                node.value = value;
                return oldValue;
            }
        }while (node != null);
        // 看看插入到父节点的哪个位置
        Node<K,V> newNode = createNode(key, value, parent);
        if (cmp > 0) {
            parent.right = newNode;
        } else {
            parent.left = newNode;
        }
        size++;
        // 新添加节点之后的处理
        fixAfterPut(newNode);
        return null;

    }

    @Override
    public V get(K key) {
        Node<K, V> node = node(key);
        return node != null ? node.value : null;
    }

    @Override
    public V remove(K key) {
        return remove(node(key));
    }

    @Override
    public boolean containsKey(K key) {
        return node(key) != null;
    }

    @Override
    public boolean containsValue(V value) {
        if (size==0) return false;
        Queue<Node<K,V>> queue = new LinkedList<>();
        for (int i = 0; i < table.length; i++) {
            if (table[i]==null) continue;
            queue.offer(table[i]);
            while (!queue.isEmpty()) {
                Node<K,V> node = queue.poll();
                if (Objects.equals(value,node.value))return true;

                if (node.left != null) {
                    queue.offer(node.left);
                }
                if (node.right != null) {
                    queue.offer(node.right);
                }

            }

        }
        return false;
    }

    @Override
    public void traversal(Visitor<K, V> visitor) {
        if (size==0 || visitor==null) return ;
        Queue<Node<K,V>> queue = new LinkedList<>();
        for (int i = 0; i < table.length; i++) {
            if (table[i]==null) continue;
            queue.offer(table[i]);
            while (!queue.isEmpty()) {
                Node<K,V> node = queue.poll();
                if (visitor.visit(node.key,node.value))return ;

                if (node.left != null) {
                    queue.offer(node.left);
                }
                if (node.right != null) {
                    queue.offer(node.right);
                }

            }

        }
    }

    public void print(){
        if (size==0 ) return;
        for (int i = 0; i < table.length; i++) {
            final Node<K,V> root = table[i];
            System.out.println("[index="+i+"]");
            BinaryTrees.println(new BinaryTreeInfo() {
                @Override
                public Object root() {
                    return root;
                }

                @Override
                public Object left(Object node) {
                    return ((Node<K,V>)node).right;
                }

                @Override
                public Object right(Object node) {
                    return ((Node<K,V>)node).left;
                }

                @Override
                public Object string(Object node) {
                    return node;
                }
            });
            System.out.println("----------------------------");
        }
    }

    protected Node<K,V> createNode(K key, V value, Node<K, V> parent) {
        return new Node<>(key, value, parent);
    }



    protected V remove(Node<K,V> node) {
        if (node == null)return null;

        Node<K, V> willNode = node;

        size--;

        V oldValue = node.value;
        if (node.hasTwoChildern()) {//度为2个节点
            //找到后继节点
            Node<K, V> s = successor(node);
            //用后继节点的值覆盖度为2的节点的值
            node.key = s.key;
            node.value = s.value;
            node.hash = s.hash;
            //删除后继节点
            node = s;

        }


        //删除node节点(node的度必然是1或者0)
        Node<K, V> replacement = node.left != null ? node.left : node.right;
        int index = index(node);

        if (replacement != null) {// node是度为1的节点
            //更改parent
            replacement.parent = node.parent;
            //更改parent left、right的指向
            if (node.parent == null) {//node是度为1的节点并且是根节点
                table[index] = replacement;
            }
            else if (node == node.parent.left) {
                node.parent.left = replacement;

            } else {// (node == node.parent.right)
                node.parent.right = replacement;
            }
            //被删除的节点-调整
            fixAfterRemove(replacement);
        } else if (node.parent == null) {//node是叶子节点并且是根节点
            table[index] = null;

            //被删除的节点-调整
            fixAfterRemove(node);
        } else {//node是叶子节点，但不是根节点
            if (node == node.parent.left) {
                node.parent.left = null;
            } else { //node == node.parent.right
                node.parent.right = null;
            }

            //被删除的节点-调整
            fixAfterRemove(node);
        }
        //交给子类去处理
        afterRemove(willNode,node);

        return oldValue;
    }

    //后继节点
    private Node<K, V> successor(Node<K, V> node){
        if (node == null) return null;

        //前驱结点在左子树当中(right.left.left.left...)
        Node<K, V> p = node.right;
        if (p != null) {
            while (p.left != null) {
                p = p.left;
            }
            return p;
        }
        //从祖父节点中寻找
        while (node.parent != null && node == node.parent.right) {
            node = node.parent;
        }

        return node.parent;
    }


    private Node<K, V> node(K key) {
        Node<K, V> root = table[index(key)];
        return root == null ? null : node(root, key);
    }

    private Node<K, V> node(Node<K,V> node,K k1) {
//        Node<K, V> node = table[index(key)];
//        int h1 = k1 == null ? 0 : k1.hashCode();
        int h1 = hash(k1);
        //存储查找结果
        Node<K, V> result = null;
        int cmp = 0;
        while (node != null) {
            /* 先注掉
            int cmp = compare(key, node.key, h1, node.hash);
            if (cmp==0) return node;

            if (cmp > 0) {
                node = node.right;
            } else if (cmp < 0) {
                node = node.left;
            }*/
            K k2 = node.key;
            int h2 = node.hash;
            //先比较哈希值
            if (h1 > h2) {
                node = node.right;
            } else if (h1 < h2) {
                node = node.left;
            }else if (Objects.equals(k1,k2)){
                return node;

            } else if (k1 != null && k2 != null
                    && k1 instanceof Comparable
                    && k1.getClass() == k2.getClass()
                    && (cmp = ((Comparable) k1).compareTo(k2)) != 0) {
                node = cmp > 0 ? node.right : node.left;
//                if (cmp > 0) {
//                    node = node.right;
//                } else if (cmp < 0) {
//                    node = node.left;
//                }
//                else {
//                    return node;
//                }
                //哈希值相等，不具备可比较性，也不equals
            } else if (node.right != null && (result = node(node.right, k1)) != null) {
                return result;
            } else {//只能往左边找
                node = node.left;
            }

//            else if (node.left != null && (result = node(node.left, key)) != null) {
//                return result;
//            } else {
//                return null;
//            }

        }
        return null;
    }


    /**
     * 根据key生成对应的索引（在桶数组中的位置）
     * @return
     */
    private int index(K key){
        return hash(key) & (table.length - 1);
    }

    private int hash(K key) {
        if (key==null) return 0;
        int hash = key.hashCode();
        return hash ^ (hash >>> 16) ;
    }

    private int index(Node<K,V> node){
//        return node.hash ^ (node.hash >>> 16) & (table.length - 1);
        return node.hash & (table.length - 1);
    }

    /**
     * 节点类
     */
    protected static class Node<K, V> {
        int hash;
        K key;
        V value;
        boolean color = RED;
        Node<K, V> left;
        Node<K, V> right;
        Node<K, V> parent;

        public Node(K key,V value, Node<K, V> parent) {
            this.key = key;
            int hash = key == null ? 0 : key.hashCode();
            this.hash = hash ^ (hash >>> 16);
            this.value = value;
            this.parent = parent;
        }

        public boolean isLeaf() {
            return left == null && right == null;
        }

        public boolean hasTwoChildern() {
            return left != null && right != null;
        }

        public boolean isLeftChild() {
            return parent != null && this == parent.left;
        }

        public boolean isRightChild() {
            return parent != null && this == parent.right;
        }

        public Node<K, V> sibling(){
            if (isLeftChild()) {
                return parent.right;
            }
            if (isRightChild()) {
                return parent.left;
            }

            return null;
        }

        @Override
        public String toString() {
            return "Node_" + key + "_" + value;
        }
    }

    private void fixAfterRemove(Node<K, V> node) {
        //如果删除的结点是红色
        //或者用于取代删除结点的子节点是红色
        if (isRed(node)) {
            black(node);
            return;
        }

        Node<K, V> parent = node.parent;

        //删除的是根节点
        if (parent == null) return;

        //删除的是黑色叶子节点【下溢】
        //判断被删除的node是左还是右
        boolean left = parent.left == null || node.isLeftChild();
        Node<K, V> sibling = left ? parent.right : parent.left;
        if (left) {//被删除的结点在左边，兄弟节点在右边
            if (isRed(sibling)) {// 兄弟节点是红色
                black(sibling);
                red(parent);
                rotateLeft(parent);
                //更换兄弟
                sibling = parent.right;
            }
            //兄弟节点必然是黑色
            if (isBlack(sibling.left) && isBlack(sibling.right)) {
                // 兄弟节点没有一个红色子节点，父节点要向下跟兄弟节点合并
                boolean parentBlack = isBlack(parent);
                black(parent);
                red(sibling);
                if (parentBlack) {
                    fixAfterRemove(parent);
                }
            } else {// 兄弟节点至少有一个红色子节点，向兄弟节借点元素
                // 兄弟节点的左边是黑色，兄弟要先旋转
                if (isBlack(sibling.right)) {
                    rotateRight(sibling);
                    sibling = parent.right;
                }

                color(sibling, colorOf((parent)));
                black(sibling.right);
                black(parent);
                rotateLeft(parent);
            }
        } else {//被删除的节点在右边，兄弟节点在左边

            if (isRed(sibling)) {// 兄弟节点是红色
                black(sibling);
                red(parent);
                rotateRight(parent);
                //更换兄弟
                sibling = parent.left;
            }
            //兄弟节点必然是黑色
            if (isBlack(sibling.left) && isBlack(sibling.right)) {
                // 兄弟节点没有一个红色子节点，父节点要向下跟兄弟节点合并
                boolean parentBlack = isBlack(parent);
                black(parent);
                red(sibling);
                if (parentBlack) {
                    fixAfterRemove(parent);
                }
            } else {// 兄弟节点至少有一个红色子节点，向兄弟节借点元素
                // 兄弟节点的左边是黑色，兄弟要先旋转
                if (isBlack(sibling.left)) {
                    rotateLeft(sibling);
                    sibling = parent.left;
                }

                color(sibling, colorOf((parent)));
                black(sibling.left);
                black(parent);
                rotateRight(parent);
            }
        }

    }

//    private Node<K,V> node(K key) {
//        Node<K,V> node = root;
//        while (node != null) {
//            int cmp = compare(key, node.key);
//            if (cmp == 0) return node;
//            if (cmp > 0) {
//                node = node.right;
//            } else {//cmp<0
//                node = node.left;
//            }
//        }
//        return null;
//    }

    private void fixAfterPut(Node<K,V> node) {
        Node<K,V> parent = node.parent;

        // 添加的是根节点 或者 上溢到达了根节点
        if (parent == null) {
            black(node);
            return;
        }

        //如果父节点是黑色，直接返回
        if (isBlack(parent)) return;

        // 叔父节点
        Node<K,V> uncle = parent.sibling();
        // 祖父节点
        Node<K,V> grand = red(parent.parent);

        if (isRed(uncle)) {// 叔父节点是红色  [B树节点上溢]
            black(parent);
            black(uncle);
            // 把祖父节点当做是新添加的节点
            fixAfterPut(grand);
            return;
        }

        //叔父节点不是红色
        if (parent.isLeftChild()) {// L
//            red(grand);
            if (node.isLeftChild()) {// LL
                black(parent);
            } else {// LR
                black(node);
                rotateLeft(parent);
            }
            rotateRight(grand);
        } else { // R
//            red(grand);
            if (node.isLeftChild()) { // RL
                black(node);
                rotateRight(parent);
            } else {// RR
                black(parent);
            }
            rotateLeft(grand);
        }
    }

    //左旋转
    private void rotateLeft(Node<K,V> grand) {
        Node<K,V> parent = grand.right;
        Node<K,V> child = parent.left;
        grand.right = child;
        parent.left = grand;

        afterRotate(grand, parent, child);
    }

    //右旋转
    private void rotateRight(Node<K,V> grand) {
        Node<K,V> parent = grand.left;
        Node<K,V> child = parent.right;
        grand.left = child;
        parent.right = grand;

        afterRotate(grand, parent, child);
    }

    //统一旋转之后的处理
    private void afterRotate(Node<K,V> grand,Node<K,V> parent,Node<K,V> child){
        //更新parent的parent属性
        //让parent成为子树的根节点
        parent.parent = grand.parent;
        if (grand.isLeftChild()) {
            grand.parent.left = parent;
        } else if (grand.isRightChild()) {
            grand.parent.right = parent;
        } else {// grand是root节点
//            root = parent;
            table[index(grand)] = parent;
        }

        //更新child的parent属性
        if (child != null) {
            child.parent = grand;
        }

        //更新grand的parent属性
        grand.parent = parent;
    }

    private Node<K,V> color(Node<K,V> node, boolean color) {
        if (node == null) return node;
        node.color = color;
        return node;
    }

    //染色
    private Node<K,V> red(Node<K,V> node) {
        return color(node,RED);
    }

    //染色
    private Node<K,V> black(Node<K,V> node) {
        return color(node,BLACK);
    }

    private boolean colorOf(Node<K,V> node){
        return node == null ? BLACK : node.color;
    }

    private boolean isBlack(Node<K,V> node) {
        return colorOf(node) == BLACK;
    }

    private boolean isRed(Node<K,V> node) {
        return colorOf(node) == RED;
    }

    /**
     * 比较key大小
     * @param k1
     * @param k2
     * @param h1
     * @param h2
     * @return
     */
    private int compare(K k1, K k2,int h1,int h2) {
        // 比较哈希值
        int result = h1 - h2;
        if (result != 0) return result;

        //比较equals
        if (Objects.equals(k1, k2))return 0;

        //哈希值相等，但是不equals
        if (k1 != null && k2 != null
                && k1.getClass() == k2.getClass()
                && k1 instanceof Comparable) {
            // 同一种类型并且具备可比较性
            if (k1 instanceof Comparable) {
                return ((Comparable)k1).compareTo(k2);
            }

            //比较类名
//            String k1Cls = k1.getClass().getName();
//            String k2Cls = k2.getClass().getName();
//            result = k1Cls.compareTo(k2Cls);
//            if (result != 0) return result;


        }

        // 同一种类型，哈希值相等，但是不具备可比较性
        // k1不为null，k2为null
        // k1为null，k2不为null
        return System.identityHashCode(k1) - System.identityHashCode(k2);
    }

    //交换节点/替换节点
//    protected void replaceNode(){
//
//    }

    protected void afterRemove(Node<K, V> willNode, Node<K, V> removeNode) {


    }

    private void resize() {
        // 装填因子 <= 0.75
        if (size / table.length <= DEFAULT_LOAD_FACTOR) return;

        Node<K, V>[] oldTable = table;
        table = new Node[oldTable.length << 1];

        Queue<Node<K, V>> queue = new LinkedList<>();
        for (int i = 0; i < oldTable.length; i++) {
            if (oldTable[i] == null) continue;

            queue.offer(oldTable[i]);
            while (!queue.isEmpty()) {
                Node<K, V> node = queue.poll();
                if (node.left != null) {
                    queue.offer(node.left);
                }
                if (node.right != null) {
                    queue.offer(node.right);
                }

                // 挪动代码得放到最后面
                moveNode(node);
            }
        }
    }

    private void moveNode(Node<K, V> newNode) {
        //重置
        newNode.parent = null;
        newNode.left = null;
        newNode.right = null;
        newNode.color = RED;

        int index = index(newNode);
        //取出index位置的红黑树根节点
        Node<K, V> root = table[index];
        if (root == null) {
            root = newNode;
            table[index] = root;
            fixAfterPut(root);
            return;
        }
        //哈希冲突，添加新的节点到红黑树上
        // 添加的不是第一个节点
        // 找到父节点
        Node<K,V> parent = null;
        Node<K,V> node = root;
        int cmp = 0;
        K k1 = newNode.key;
        int h1 = newNode.hash;
        do{
//            cmp = compare(key, node.key, h1, node.hash);
            parent = node;
            K k2 = node.key;
            int h2 = node.hash;
            if (h1 > h2) {
                cmp = 1;
            } else if (h1 < h2) {
                cmp = -1;
            } else if (k1 != null && k2 != null
                    && k1 instanceof Comparable
                    && k1.getClass() == k2.getClass()
                    && (cmp = ((Comparable) k1).compareTo(k2)) != 0) {
            }  else {
                cmp = System.identityHashCode(k1) - System.identityHashCode(k2);

            }



            if (cmp > 0) {
                node = node.right;
            } else if (cmp < 0) {
                node = node.left;
            }
        }while (node != null);
        // 看看插入到父节点的哪个位置
        newNode.parent = parent;
        if (cmp > 0) {
            parent.right = newNode;
        } else {
            parent.left = newNode;
        }

        // 新添加节点之后的处理
        fixAfterPut(newNode);

    }
//
//    //检查值是否为空
//    private void keyNotNullCheck(K key) {
//        if (key == null) {
//            throw new IllegalArgumentException("key must not be null");
//        }
//    }



}
